A spokesman cites "an unavoidable conflict" as the reason for the first missed meeting in memory.

The 88-year-old, who lives in LA and is also executive chairman and controlling shareholder of CBS Corp., will leave most of the proceedings to president and CEO Philippe Dauman. "Due to an unavoidable conflict, Mr. Redstone will be addressing the shareholder's at Viacom's annual meeting in a video presentation," his spokesman said without detailing the conflict.

Redstone, who has over the past few years scaled back his public appearances, has presided over Viacom's shareholder meetings as long as observers can remember. The spokesman said he couldn't recall when Redstone last missed a meeting.

Asked about the chairman's health, the spokesman said "Sumner is fine." He added: "He is looking forward to getting his Hollywood star" on the Walk of Fame at the end of the month. Redstone also attended the Oscars on Sunday.

The LA Times first reported that Redstone would miss the Viacom shareholder affair.

At last year's annual meeting of Viacom shareholders at the company's Times Square headquarters, Redstone touted the "growing number of hits" on the company's cable networks and the performance of Paramount Pictures.

He also introduced his long-time confident Dauman in his typical complimentary fashion as a "genius" and viewed that "our best days are yet to come."

It wasn't immediately clear if he would travel to New York for CBS Corp,'s annual shareholder meeting later this spring. The spokesman said he didn't know. At last May's CBS meeting, he celebrated his 88th birthday with a bullish gathering.